Wireless communications systems are used in a variety of telecommunications systems, television, radio and other media systems, data communication networks, and other systems to convey information between remote points using wireless transmitters and wireless receivers. A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. Transmitters often include digital signal processing circuits which encode a data signal, upconverts it to a radio frequency signal, and passes it signal amplifiers which receive the radio-frequency, amplify the signal by a predetermined gain, and transmit the amplified signal through an antenna. On the other hand, a receiver is an electronic device which, also usually with the aid of an antenna, receives and processes a wireless electromagnetic signal. In certain instances, a transmitter and receiver may be combined into a single device called a transceiver.
Many wireless transceivers may suffer from phase shifts in a transmit path due to changes in radio frequency (RF) gain, bias, and/or load of the transmit path. Such phase shifts may cause numerous problems in a wireless communication device. For example, random signal phase shifts may cause magnitude measurement errors when a coherent receiver is used, and the magnitude error signal is generated from the difference between the coherent receiver output and a reference waveform. These signal phase distortions in RF gain stages of a transmit path may contribute to differential non-linear errors (DNLEs) in wireless transmitters. Such DNLEs may accumulate throughout the transmit path, leading to integral non-linear gain error (INLE). Such DNLEs and INLE may lead to degradation of power accuracy at the output of the transmit path. Such phase shifts may also result in degradation of adjacent channel leakage ratio (ACLR) and error vector magnitude (EVM) in a wireless communication device, and/or loss or carrier tracking synchronization between the wireless communication device and a base station, potentially leading to dropped calls and/or other performance degradation.